PVDF/PBI membrane incorporated with SAPO-34 zeolite for membrane gas absorption

Abstract

Polymeric membranes with low surface energy and large pore size are most desirable in membrane gas absorption (MGA). In this paper, PVDF membrane was incorporated with gas selective SAPO-34 zeolite and blended with hydrolytically stable polybenzimidazole (PBI) to engineer a membrane contactor with additional functionality and stability. The effects of inorganic fillers and PBI on the membranes properties and the CO2 absorption performance were studied. In addition, the results were compared to PVDF membrane with PBI, modified and unmodified SAPO-34 zeolite. The hydrophilic SAPO-34 zeolite was modified into the hydrophobic SAPO-34 zeolite using fluorocarbon silane. The CO2 flux of PVDF membrane increased 60% when it was blended with 10wt% of SAPO-34. The presence of SAPO-34 in PVDF membrane enriched membrane porosity and affinity towards CO2. The PVDF membrane with hydrophobic SAPO-34 exhibited a dense membrane structure, resulting in a great membrane resistance for CO2 transfer. Although PVDF membrane with both PBI and SAPO-34 (P-5S34-5PBI) showed lower CO2 flux than the PVDF membrane with SAPO-34 (P-10S34), the addition of 5wt% of PBI provided better membrane stability in the corrosive solution.